This invention is direct mean for controlling the lateral edge locations of a roll window screen in a window opening or other opening in a wall.
A frame with which the invention may be used defines a window opening and a screen opening or a screen opening alone. This opening is often closable on the building""s outer side by a pivotally mounted casement window comprising a glazing unit in a frame hinged to open outwardly relative to the building wall. The opening is closable or partially closable on the building""s inner side by a screen, which is, in rolled up attitude, wound like a window blind on a roll located on the frame member at one side of the opening, which may be longitudinally unrolled to a partially or fully extended position. The screen has lateral edges and has, between those edges, an area intended to close the window opening to the extent of the screen""s extension. Although the rolled up screen may be located at the top, bottom or either side of the opening it is usually located at the top.
Difficulty is presently encountered with existing screens because the lateral screen edges tend, in use, to migrate or pull away laterally inwardly toward each other. Such migration and pulling away will leave open areas on one or both lateral sides of the extended portion of the screen and also leaves an untidy impression. Present screen and frame designs do not prevent such inward migration or pulling away.
This invention provides distinct features of the screen and the frame, which act so that the screen edges close the opening between lateral sides and do not migrate or xe2x80x98pull awayxe2x80x99 from the lateral edges.
The inventive screen and its mounting are usually found in a frame installed in a building wall opening. Such a frame, toward the outside of the building from the screen, usually mounts a glazing unit which is hinged to swing outwardly relative to the building while the frame mounts a screen inwardly from the closed position of the window movable between extended and retracted position.
In accord with the invention the frame is provided with means for mounting a screen roll in position to unwind, to partially extended or extended position in the window opening, usually under control of a draw bar. In winding or unwinding, the lateral edges of the screen follow paths designed to be outside of the edges of the window opening. The screen may be of any material which is flexible enough to roll on a roller, such as plastic or aluminum mesh or fibreglass coated with plastic.
In accord with the invention, the frame provides two spaced members defining slots facing each other and extending along the screen path and the slots are dimensioned to receive the partially extended screens near the lateral edges so that, on each side, the edges are laterally outwardly of the slots. The lateral edges of the screens are then shaped or combined with frame based members so that the screen lateral edges are prevented from travelling inwardly through the slots and are maintained laterally outwardly of the slots, whether the screen is travelling or stationary, resulting in the closing of that part of the opening between the lateral screen edges and providing a neat appearance for the screen.
Screens for use with the invention are typically although not necessarily composed of fibreglass coated with plastic. They are designed to roll up in a relatively compact roll in the retracted position. Thus any modification to the screen, to assist it in operating in accord with the invention, must not unduly interfere with its relatively compact rolling qualities. The retracted position of the screen is usually above the top of the window opening so that the free edge of the screen moves to the frame bottom to close the opening. However the screen roll can be at one side of the window opening so that it unrolls to extended position at the opposite side. The screen roll can alternatively be at the lower side of the window opening provided if there are means to retain the draw bar in place at selected settings.
In a preferred form of the invention, in the path of each edge adjacent, respective lateral sides of the screen, a rod is provided (laterally outwardly of each slot), from an attachment to the frame beyond screen extension travel, to a free end adjacent the roll position. The screen is preferably folded or welded and glued, to provide a tube at each lateral edge the tube being dimensioned to ride on the post. The screen where it is folded and welded or glued to form a sleeve must in positions which in the travel of the screen are free of the rod, be able to be flattened to a relatively thin size to wind on the roller.
The screen where the pocket surrounds the rod has a thickness which is diametrically larger than that of the slot. Thus the screen, partially extended must extend from the rod on one side through a slot, across the opening between the extended positions and through the other slot. Thus the action of the slots to prevent inward movement of the bolt-swollen screen edges, maintains both the closure between the lateral edges and the neat appearance of the screen.
Alternatives are within the scope of the invention. Alternate means are described for shaping or treating the screen adjacent the lateral edges so that they must stay laterally outside of the slots.
An alternative to the tube surrounding the screen tubes, involves the provision of each screen, with edge adjacent strips which may be strengthened relative to the strip, if necessary. The strips are located to be outside the slots which receive a partially extended screen. The strips are mini-slotted regularly to receive conveyor teeth. An endless belt with teeth is mounted to rotate with the teeth finding the mini slots while the teeth are transverse to the slot. Thus the teeth, located outside the frame slot, prevent escape of the strip edges of the screen through the slots and maintain a neat appearance of the screen.